[racket-dev] [plt] Push #28829: master branch updated

Based on this commit, I feel like "assert" would be a better name than
"invariant-assertion". I can imagine putting these on various internal
parts of a function where the self-blame would be justified. The
(define id (assert ctc e)) pattern is just one common use.

Jay

On Sat, May 31, 2014 at 1:46 PM,  <matthias at racket-lang.org> wrote:
> matthias has updated `master' from 9d94ef725e to 89dea63995.
>   http://git.racket-lang.org/plt/9d94ef725e..89dea63995
>
> =====[ One Commit ]=====================================================
> Directory summary:
>   84.2% pkgs/racket-pkgs/racket-doc/scribblings/reference/
>   11.0% racket/collects/racket/contract/private/
>    4.6% racket/collects/racket/contract/
>
> ~~~~~~~~~~
>
> 89dea63 Matthias Felleisen <matthias at racket-lang.org> 2014-05-31 15:45
> :
> | removed _contract_ language from _invariant-..._ as much as possible
> |
> | added a hint as to why the error message uses the inappropriate contract language
> :
>   M racket/collects/racket/contract/private/base.rkt  |  4 ++--
>   M racket/collects/racket/contract/region.rkt        |  2 +-
>   M .../scribblings/reference/contracts.scrbl         | 22 ++++++++++----------
>
> =====[ Overall Diff ]===================================================
>
> pkgs/racket-pkgs/racket-doc/scribblings/reference/contracts.scrbl
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> --- OLD/pkgs/racket-pkgs/racket-doc/scribblings/reference/contracts.scrbl
> +++ NEW/pkgs/racket-pkgs/racket-doc/scribblings/reference/contracts.scrbl
> @@ -1509,24 +1509,24 @@ The @racket[define-struct/contract] form only allows a subset of the
>  (make-salmon #f 'pacific)
>  ]}
>
> - at defform[(invariant-contract contract-expr expr)]{
> -  Establishes an invariant of @racket[expr], determined by @racket[contract-expr].
> + at defform[(invariant-assertion invariant-expr expr)]{
> +  Establishes an invariant of @racket[expr], determined by @racket[invariant-expr].
>
> -  Unlike other ways to attach contracts to values, an
> -  @racket[invariant-contract] does not establish a boundary
> -  between two parties. Instead, it simply puts the contract
> -  on the value, treating the module containing the
> -  @racket[invariant-contract] expression as the party to be blamed
> -  for any violations of the contract.
> +  Unlike the specification of a contract, an
> +  @racket[invariant-assertion] does not establish a boundary
> +  between two parties. Instead, it simply attaches a logical assertion
> +  to the value. Because the form uses contract machinery to check the
> +  assertion, the surround module is treated as the party to be blamed
> +  for any violations of the assertion.
>
> -  This means, for example, that the contract is checked on
> +  This means, for example, that the assertion is checked on
>    recursive calls, when an invariant is used on the right-hand
> -  side of a definition.
> +  side of a definition:
>
>    @examples[#:eval
>              furlongs->feet-eval
>              (define furlongss->feets
> -              (invariant-contract
> +              (invariant-assertion
>                 (-> (listof real?) (listof real?))
>                 (λ (l)
>                   (cond
>
> racket/collects/racket/contract/private/base.rkt
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> --- OLD/racket/collects/racket/contract/private/base.rkt
> +++ NEW/racket/collects/racket/contract/private/base.rkt
> @@ -3,7 +3,7 @@
>  (provide contract
>           (rename-out [-recursive-contract recursive-contract])
>           current-contract-region
> -         invariant-contract)
> +         invariant-assertion)
>
>  (require (for-syntax racket/base syntax/name syntax/srcloc)
>           racket/stxparam
> @@ -89,7 +89,7 @@
>            (procedure-rename new-val vs-name)])]
>        [else new-val])))
>
> -(define-syntax (invariant-contract stx)
> +(define-syntax (invariant-assertion stx)
>    (syntax-case stx ()
>      [(_ ctc e)
>       (quasisyntax/loc stx
>
> racket/collects/racket/contract/region.rkt
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> --- OLD/racket/collects/racket/contract/region.rkt
> +++ NEW/racket/collects/racket/contract/region.rkt
> @@ -4,7 +4,7 @@
>           define/contract
>           with-contract
>           current-contract-region
> -         invariant-contract)
> +         invariant-assertion)
>
>  (require (for-syntax racket/base
>                       racket/struct-info



-- 
Jay McCarthy <jay at cs.byu.edu>
Assistant Professor / Brigham Young University
http://faculty.cs.byu.edu/~jay

"The glory of God is Intelligence" - D&C 93